Networks of the kind mentioned above are disclosed in JP-A-61-169042 and the U.S. Pat. Nos. 4,049,906, 4,625,306, 4,651,318. In these prior systems there is in each transferred message an address portion by means of which the information packet is guided or routed through the switching nodes of said systems.
In the transfer over a data network of messages of type switching messages for an automatic telephone network often a receipt is required to prove that the transferred message has arrived correctly to the receiving station. The receipt message then has to be provided with a return address indicating the original source station. In the transfer of short messages of the kind mentioned it is important that the messages should not be unduely prolonged by complicated addresses of the source station and the receiving or destination station. A method of solving this problem, used for the address of the receiving station, is described in the three first, above mentioned documents. Thus in each transferred message there is an address portion. This address portion contains information especially directed to the nodes informing the nodes of the output line on which the message is to be sent from the node. The part of the address information in the information packet which is relevant to the node is then removed in the node, when the node has used its address information to select one of several possible output lines. In this way the message will be shorter when it approaches its destination.